1. Field of the Invention
The present invention relates to an optical waveguide device such as a traveling wave optical modulator.
2. Background Arts
The present applicant has disclosed a configuration where a thin portion is provided under optical waveguides of a substrate of a traveling wave optical modulator, and the thickness of the thin portion is equal to or less than 10 μm, for example, in Japanese Laid-Open Patent Publication (Kokai) No. H10-133159A and Japanese Laid-Open Patent Publication (Kokai) No. 2002-169133A. With this configuration, optical modulation can be advantageously carried out at a high speed without forming a buffer layer made of silicon oxide while a product (Vπ·L) of a drive voltage Vπ and the length L of electrodes can be reduced.